The $25 Raspberry Pi 3 Model A+ is the latest single-board computer from the venerable Raspberry Pi Foundation. The Model A+ boasts the same CPU and wireless connectivity as its bigger brother, the Model B+, but shaves off some I/O for the sake of thinness. Notably missing are three out of four USB ports and the Ethernet jack.
https://www.notebookcheck.net/Raspberry-Pi-3-Model-A-retains-the-power-of-the-Model-B-in-a-smaller-cheaper-package.362986.0.html